Build airtight and save costs
The Ultimate Guide to Nearly Zero Energy Building
DownloadWhat can you expect from an airtightness workshop CPD in your office - make low energy building easier.
“You can’t learn tailoring just by watching Youtube”
You need to handle fabric to feel its qualities; how it drapes, how to join it and how to master it.
SIGA feel the same about airtightness. To design comfortable and efficient buildings you must know how to build airtight. To understand the capabilities of the product you need to handle it. I recently joined a CPD session to learn what SIGA offers.
HNW architects in Chichester asked SIGA for a practical hands-on demonstration of the product. HNW work at a variety of scales in numerous sectors.
The typical airtightness HNW currently achieve is 3 to 5 m3/hr/m2@50pa
HNW want to confidently push further than this. Improved comfort and efficiency are a real differentiator for the tenants of their buildings.
SIGA reps Michael and Sean have tweaked the content for HNW’s specific needs and requirements. Not only the global imperative of climate change, but also the personal motivation of health and comfort drive us to build airtight yet moisture-safe, breathable and toxin-free homes and workplaces.
The session kicks off with an overview of the reasons why we need airtight yet moisture-safe, breathable and toxin-free homes and workplaces. The bespoke agenda continues with a run-through the essential building physics of moisture in buildings;
(we’ll cover moisture safe construction in more detail in a later blog)
Responding to the brief given by the host, we get to handle some of the main tapes and membranes in the SIGA catalogue.
SIGA’s Sicrall® 60 is a highly adhesive tape for sealing
Sicrall is the yellow tape- ideal for joining membrane to membrane. Sicrall is designed for easy application; it doesn’t sag, tears by hand, it can easily be applied on long lengths; sticks straight onto OSB or timber.
Alternatively, installers may use Cloth or gaffer tape, but SIGA testing found that the adhesive degrades overtime. Eventually it becomes powdery and finally, after 4-10 years, it gives up altogether.
Sean and Michael demonstrate the key features. Then, it’s over to us. Each table has a mock-up section of roof on which we get to practice using the products. One participant told us:
“To practice using the products gives us invaluable insights into how the product handles. Also, it helps us to create better designs and specifications”
Rissan® is more stretchy than Sicrall, which means it’s ideal for difficult corners such as duct, pipe, wire or joist penetrations of the membrane. An alternative to this is a neoprene grommet- arguably better looking, yet at significant extra expense, and with much less adaptability than tape.
Again, we get to handle the product, we get a feel for how much space to leave installers to do a good job on installing.
Detailing around a window brings special challenges. Here you are dealing with 3-D right-angle corners within frames. We trialled simple origami-like details to ensure a continuous air & vapour control layer (AVCL) and weather layer. If you have these details demonstrated to you, it’s a cinch to do.
Corvum® tape with pre-fold. Note how the adhesive is proud of the backing
Corvum® 12/48 is a pre-folded tape. See how the adhesive is proud of the backing? This means it will fill & seal the internal corner completely. That’s a patented feature.
“12/48” means the fold widths are 12mm, and 48mm. 12mm is just shy of 12.5mm; as you know this is the depth of plasterboard. So, the tape won’t show once it’s drylined. Its clever stuff!
Demonstration of Corvum® pre-folded tape as used for inside of a window.
Majrex® is an intelligent membrane that uniquely allows moisture to travel in one direction only. We learned how this patented product can change the way you design roofs and walls.
On the outer weathering layer, we need products which are significantly lower moisture resisting; with a lower Sd value. We get to apply Majvest® and Wigluv® tape to the mock-up.
Outer weathering layer application
Both product ranges are super sticky (of course), fully weatherproof, and low Sd value. Did we mention non-toxic and long lasting?
SIGA Fentrim® 3 50/85
Fentrim® is a bit of a brute. It is available in widths up to 300mm wide. It is stickier than the stickiest thing I can think of right now (the price tag an embarrassingly cheap bottle of wine I brought to a recent dinner party).
You’ll find Fentrim® goes on cleaner, quicker, cheaper and more robustly than the alternative method of adhering EPDM sheets with tubes of mastic. We go into more detail in this blog.
Fentrim® tape with pre-folded edge to allow easy application. The backing edge is proud to make it easy to peel off.
SIGA are serious about product development. They engage their customers to find out where needs are & they follow that through to market. Hence the product range is pretty extensive. And, as their R&D process is exhaustive and intensive the products are feature-rich. The CPD gives you an overview of the range so it’s less overwhelming. It means you can find the product that meets the need precisely & effectively.
At the end of the session Michael and Sean answered any questions from the participants on airtightness. This helped to settle a few arguments and dissolve a few myths.
HNW were certainly pleased with the content. One participant told us:
“Its given me more confidence in specifying higher performing buildings”
Getting a hold of the tapes and membranes, and practicing installing them gives specifiers invaluable insight into how to improve their designs and product selections. It gives designers more confidence in specifying higher-performing buildings. It gives the guys on site the best chance of doing an excellent job.
These CPDs are free of charge; it’s part of the improved service SIGA offers its customers:
• CPDs
• Design reviews
• Moisture risk calculations
• Special products- minimum order in low quantity
• Warranties
• On-site training
Bertie has practised building services engineering and sustainability consulting in the UK for 15 years. He is a certified PassivHaus planner. He is on a mission to help you deliver a high-quality building, one that does what it says on the tin.
Added to my cart